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Stimulus-specific Cortical Visual Evoked Potential Morphological Patterns
Published on: May 12, 2019
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Visual percepts evoked with an intracortical 96-channel microelectrode array inserted in human occipital cortex
Eduardo Fernández1,2,3, Arantxa Alfaro1,2,4, Cristina Soto-Sánchez1,2
1Bioengineering Institute and Cátedra Bidons Egara, University Miguel Hernández, Elche, Spain.
The Journal of Clinical Investigation
|October 19, 2021
Summary
This study implanted a 96-electrode array into the visual cortex of a blind individual, successfully restoring rudimentary sight. The cortical visual prosthesis enabled letter identification and object boundary recognition.
Area of Science:
- Neuroscience
- Biomedical Engineering
- Ophthalmology
Background:
- Restoring vision to blind individuals via direct visual cortex stimulation remains a significant challenge.
- No clinically viable cortical visual prosthesis currently exists to achieve this goal.
Observation:
- A 96-electrode intracortical microelectrode array was implanted in the visual cortex of a blind participant for six months.
- Stimulation thresholds and visual percepts were measured, alongside high-quality neuronal recordings.
- Chronic implantation and explantation were performed without complications.
Findings:
- Mean stimulation threshold was 66.8 ± 36.5 μA, with stable parameters over time.
- Simultaneous multi-electrode stimulation significantly reduced thresholds and evoked discriminable phosphenes.
- The participant could identify letters and recognize object boundaries using the device.
Implications:
- Demonstrates the safety and efficacy of chronic intracortical microstimulation in the human visual cortex.
- Highlights the potential of large-electrode-count cortical visual prostheses for restoring functional vision.
- Paves the way for future development of advanced neuroprosthetic devices for the blind.
